A multilayer coating provides a decorative or a protective coating on a substrate. The multilayer coating on a substrate employs at least two coating layers which may be any combination of electrocoat, primer, filler, pigmented basecoat, and clearcoat coating layers. The multilayer coating may be obtained by first applying a powder primer to a bare or electrocoated substrate. Over the primer layer, other coatings such as the basecoat and clearcoat may be applied. In some instances, a basecoat is applied over the primer and then a clearcoat layer of a coating is applied over the basecoat. Where a two color coating is desired, different approaches may be taken. In one approach, one color basecoat may be applied to part of a primer-coated substrate, then a clearcoat is applied to the entire substrate, followed by application of a different color basecoat to the remainder of the substrate, and finally a clearcoat layer being applied over all. Alternatively, one primer-coated area may be painted with basecoat, followed by application of the clearcoat, and curing of both layers together or sequentially. The area is then covered to protect it from a second color. Subsequently, a second primer-coated area is coated with a different color basecoat, then coated with clearcoat, and the layers are cured together or sequentially.
It is highly desirable to provide a multilayer coating system which promotes intercoat adhesion. The present invention is directed to a method for forming a multilayer coating promoting intercoat adhesion. The present invention is further directed to a method for forming a multilayer coating, promoting intercoat adhesion between a primer layer and a clearcoat layer in direct contact with each other.